Nanocomposites obtained from Ni-based layered double hydroxides pyrolysis: structural characterization and properties investigation

Abstract

The interest on the development of new materials for energy conversion and storage has increased in the last few years, as requirements on performance and renewability are reaching ever higher demanding levels. In this context, electrochemical devices, such as supercapacitors, new batteries and fuel cells, stands out. Thus, nanocomposites based on nanocarbons and layered double hydroxides containing transition metals (TM-LDHs) are promising materials, since their synergistic combination leads to outstanding properties. Specially what concerns supercapacitors, these materials combine high surface area and conductivity of nanocarbons, and redox activity and high specific capacitance of TM-LDHs. This project aims complement the results already obtained on Fapesp project Development of hierarchical structures with nanoarchitectures based on inorganic layered units (2014/04816-8). The composites studied have been synthesized through two routs: (i) pyrolysis of organic polymer intercalated into LDH; and (ii) synthesis of LDH onto graphene oxide (GO) surface, with further thermal treatment. The obtained materials have been characterized by a set of techniques, which will be complemented by in situ X-ray diffraction under heating and N2 atmosphere; X-ray photoelectron spectroscopy, XPS; transmission electron microscopy, TEM; surface area and porosity measurements via gas adsorption; and electrochemical characterization through cyclic voltammetry and galvanostatic charge discharge measurements.